Decreased HECTD1 mRNA expression is associated with poor prognosis and enhanced mitochondrial cellular respiratory function in breast cancer
Abstract HECT domain E3 ubiquitin ligase 1 (HECTD1) has been reported to be a negative regulator of epithelial-mesenchymal transition and to decrease breast cancer invasion and metastasis. However, the clinical significance and detailed role of HECTD1 in breast cancer remain elusive. We investigated the role of HECTD1 in two large breast cancer cohorts using mRNA and protein expression, and bioinformatics. We examined the prognostic significance of HECTD1 by multivariate analysis. HECTD1 mRNA expression (HECTD1 expression) was lower in breast cancer compared with adjacent normal tissues. HECTD1 expression levels also differed among breast cancer subtypes. Decreased HECTD1 expression was significantly associated with aggressive tumour characteristics, including large tumour size and high histological grade. HECTD1 expression was inversely associated with mitochondrial cellular respiratory function and reactive oxygen species in breast cancer tissues. Multivariate analysis identified low HECTD1 mRNA expression level as an independent risk factor for disease-free (P = 0.009) and overall (P = 0.046) survival among breast cancer patients. There was no association of HECTD1 protein expression with mRNA expression and prognosis. HECTD1 mRNA expression is a candidate prognostic biomarker in breast cancer. The poor prognosis of patients with low HECTD1 mRNA expression may be associated with increased mitochondrial respiratory function.